As for the prompts, I routinely erase all traces of past prompts I have used. Before I imported my Tumblr feed to here, though, I used to get prompts via my Tumblr inbox. And, on the rare occasions that I actually run OUT of prompts, there's a few writing prompt tumblrs I follow just to get some to hold me over.

All prompted stories are labelled, "Challenge #SERIALNUMBER:" so people can keep them straight.